REFRIGERANT CHARGE PROCEDURE (for totally dry system only)
FINALLY GOT AROUND TO CHARGING MY R-12 AC SYSTEM (it was too hot in my garage he-he) I REPLACED MY EVAP UNIT WHICH WAS LEAKING – WENT TO REBUILD THE COMPRESSOR AND FOUND THE DISCS WERE A LITTLE BIT CORRODED SO REPLACED THE COMPRESSOR AS WELL. THE 91/92 HIGH PRESSURE SERVICE PORT (SMALL ONE ON THE LEFT FENDER) WILL NEED AN ADAPTER FITTING - SM NOTED ADAPTERS NOT AVAILABLE - PER DREW I USED THE “FOUR SEASONS” BRAND #59606(from amazon). WHILE NOT REQUIRED I FLUSHED THE HARD LINES WITH “TEMPSELECT” SOLVENT WITH A SMALL PRESSURE BOTTLE KIT (both from NAPA) AND THEN BLEW DESICANT DRIED COMPRESSED AIR THRU EACH LINE ONE BY ONE FOR A FEW MINUTES EACH. SINCE YOU CAN’T BE SURE OF THE AMOUNT OF OIL CHARGE ALREADY IN YOUR NEW COMPRESSOR, I DRAINED THE OIL AND REPLACED. MY NEW DENSO COMPRESSOR(JAPAN LABEL) HAD A LOT OF METAL SHAVINGS IN IT! YOU CAN’T GET ALL THE OIL OUT THUS I HAD TO ESTIMATE (GUESS) THAT ¾ OZ WAS RETAINED. HONDA’S SPECIFIED OIL CHARGE IS 5 OZ (R-12 ONLY), SO I PUT 4 ¼ oz OF NEW MINERAL OIL(TYPE ON COMP TAG) DIRECTLY INTO THE COMPRESSOR ITSELF THUS NEEDING NO ADDITIONAL OIL DURING THE CHARGE CYCLE. IT’S MY UNDERSTANDING THAT FOR A TOTALLY DRY SYSTEM IF THE FREON AND OIL CHARGE IS CORRECT THE RESULTING GAGE PRESSURES ARE ONLY NEEDED TO ENSURE PRESSURES ARE WITHIN A TOLERABLE RANGE - IE NOT TOO HIGH. A 134A SYSTEM WILL BE THE SAME EXCEPT FOR FREON AND OIL CHARGE TYPE AND AMOUNT AND RESULTING GAGE PRESSURES WILL SLIGHTLY DIFFERENT. NOTE THAT MANIFOLD GAGES READ REGARDLESS OF WHETHER IT’S VALVES ARE OPEN OR CLOSED.
CLOSE MANIFOLD VALVES & CONNECT RED/HIGH PRESSURE HOSE OVER LEFT FENDER AND BLUE/LOW PRESSURE NEAR HEATER VALVE AND THEN YELLOW TO VACUUM PUMP - START PUMP - OPEN BLUE AND THEN RED MANIFOLD VALVES –RUN PUMP 30-45 MINUTES - SHOULD SEE MIN 29 INCHES NEGATIVE OR MORE – CLOSE BOTH MANIFOLD VALVES - LET SIT FOR EXTENDED PERIOD - IF NEEDLES DROP AT ALL, ADD DYE, OBSERVE AND FIX. IF GOOD THE HIGH(RED) MANIFOLD VALVE STAYS CLOSED THE ENTIRE CHARGE PROCESS.
SET DASH AC UNIT MIN COLD TEMP – VENT – FRESH AIR - PLACE THERMOMETER IN AC DASH VENT
PLACE SMALL BOX FAN ON RADIATOR – OPEN ENGINE HATCH AND DOORS
CONNECT BOTTOM FITTING OF YELLOW SERVICE LINE TO REFRIGERANT TANK - PLACE REFRIGERANT ON SCALE AND NOTE REFERENCE WEIGHT
OPEN REFRIGERANT VALVE AND BLEED YELLOW HOSE (LOOSEN FITTING AND LET GAS ESCAPE FOR A COUPLE OF SECONDS) AT MANIFOLD AND TIGHTEN - OPEN LOW PRESSURE BLUE MANIFOLD VALVE
START ENGINE AND RIG ACCELERATOR CABLE TO 1200 TO 1500 RPM (SMALL SHIM OF WOOD UNDER TB LEVER)
VERIFY COMPRESSOR CLUTCH ROTATION VISUALLY
MONITOR SCALE AND CLOSE BLUE MANIFOLD VALVE AT 32 TO 34 OUNCES UNDER REFERENCE WEIGHT (TOOK ABOUT 5 MINUTES). DASH THERMO SHOULD BE 50F OR LESS (I GOT 43!)
OBSERVE BLUE GAGE READINGS WHICH SHOULD BE IN THE 30-40 PSI RANGE (I GOT 30) AND RED RANGING FROM 150-250 (I GOT 175)
RAISE DASH TEMP TO 70F OF SO AND LISTEN FOR “NORMAL” COMPRESSOR CYCLES
FEEL KIND OF SILLY NOW THAT I NEEDED TO MAKE THIS CHECKLIST. BUT SINCE I DID THUS THIS POST. ALWAYS HAD HVAC DONE FOR ME, BUT THANKS TO DREW, JOE GUTTERI AND “SOME” U-TUBE FOLKS, MY ENTIRE SYSTEM IS NOW REBUILT. I WILL NOW MOVE ON TO ANOTHER OLD R-12 VEHICLE - MY 91 TOYOTA PREVIA (yes the one that looks like a big Egg – buy hey it’s a mid-engine Egg and it runs like it’s brand new except for AC).
FINALLY GOT AROUND TO CHARGING MY R-12 AC SYSTEM (it was too hot in my garage he-he) I REPLACED MY EVAP UNIT WHICH WAS LEAKING – WENT TO REBUILD THE COMPRESSOR AND FOUND THE DISCS WERE A LITTLE BIT CORRODED SO REPLACED THE COMPRESSOR AS WELL. THE 91/92 HIGH PRESSURE SERVICE PORT (SMALL ONE ON THE LEFT FENDER) WILL NEED AN ADAPTER FITTING - SM NOTED ADAPTERS NOT AVAILABLE - PER DREW I USED THE “FOUR SEASONS” BRAND #59606(from amazon). WHILE NOT REQUIRED I FLUSHED THE HARD LINES WITH “TEMPSELECT” SOLVENT WITH A SMALL PRESSURE BOTTLE KIT (both from NAPA) AND THEN BLEW DESICANT DRIED COMPRESSED AIR THRU EACH LINE ONE BY ONE FOR A FEW MINUTES EACH. SINCE YOU CAN’T BE SURE OF THE AMOUNT OF OIL CHARGE ALREADY IN YOUR NEW COMPRESSOR, I DRAINED THE OIL AND REPLACED. MY NEW DENSO COMPRESSOR(JAPAN LABEL) HAD A LOT OF METAL SHAVINGS IN IT! YOU CAN’T GET ALL THE OIL OUT THUS I HAD TO ESTIMATE (GUESS) THAT ¾ OZ WAS RETAINED. HONDA’S SPECIFIED OIL CHARGE IS 5 OZ (R-12 ONLY), SO I PUT 4 ¼ oz OF NEW MINERAL OIL(TYPE ON COMP TAG) DIRECTLY INTO THE COMPRESSOR ITSELF THUS NEEDING NO ADDITIONAL OIL DURING THE CHARGE CYCLE. IT’S MY UNDERSTANDING THAT FOR A TOTALLY DRY SYSTEM IF THE FREON AND OIL CHARGE IS CORRECT THE RESULTING GAGE PRESSURES ARE ONLY NEEDED TO ENSURE PRESSURES ARE WITHIN A TOLERABLE RANGE - IE NOT TOO HIGH. A 134A SYSTEM WILL BE THE SAME EXCEPT FOR FREON AND OIL CHARGE TYPE AND AMOUNT AND RESULTING GAGE PRESSURES WILL SLIGHTLY DIFFERENT. NOTE THAT MANIFOLD GAGES READ REGARDLESS OF WHETHER IT’S VALVES ARE OPEN OR CLOSED.
CLOSE MANIFOLD VALVES & CONNECT RED/HIGH PRESSURE HOSE OVER LEFT FENDER AND BLUE/LOW PRESSURE NEAR HEATER VALVE AND THEN YELLOW TO VACUUM PUMP - START PUMP - OPEN BLUE AND THEN RED MANIFOLD VALVES –RUN PUMP 30-45 MINUTES - SHOULD SEE MIN 29 INCHES NEGATIVE OR MORE – CLOSE BOTH MANIFOLD VALVES - LET SIT FOR EXTENDED PERIOD - IF NEEDLES DROP AT ALL, ADD DYE, OBSERVE AND FIX. IF GOOD THE HIGH(RED) MANIFOLD VALVE STAYS CLOSED THE ENTIRE CHARGE PROCESS.
SET DASH AC UNIT MIN COLD TEMP – VENT – FRESH AIR - PLACE THERMOMETER IN AC DASH VENT
PLACE SMALL BOX FAN ON RADIATOR – OPEN ENGINE HATCH AND DOORS
CONNECT BOTTOM FITTING OF YELLOW SERVICE LINE TO REFRIGERANT TANK - PLACE REFRIGERANT ON SCALE AND NOTE REFERENCE WEIGHT
OPEN REFRIGERANT VALVE AND BLEED YELLOW HOSE (LOOSEN FITTING AND LET GAS ESCAPE FOR A COUPLE OF SECONDS) AT MANIFOLD AND TIGHTEN - OPEN LOW PRESSURE BLUE MANIFOLD VALVE
START ENGINE AND RIG ACCELERATOR CABLE TO 1200 TO 1500 RPM (SMALL SHIM OF WOOD UNDER TB LEVER)
VERIFY COMPRESSOR CLUTCH ROTATION VISUALLY
MONITOR SCALE AND CLOSE BLUE MANIFOLD VALVE AT 32 TO 34 OUNCES UNDER REFERENCE WEIGHT (TOOK ABOUT 5 MINUTES). DASH THERMO SHOULD BE 50F OR LESS (I GOT 43!)
OBSERVE BLUE GAGE READINGS WHICH SHOULD BE IN THE 30-40 PSI RANGE (I GOT 30) AND RED RANGING FROM 150-250 (I GOT 175)
RAISE DASH TEMP TO 70F OF SO AND LISTEN FOR “NORMAL” COMPRESSOR CYCLES
FEEL KIND OF SILLY NOW THAT I NEEDED TO MAKE THIS CHECKLIST. BUT SINCE I DID THUS THIS POST. ALWAYS HAD HVAC DONE FOR ME, BUT THANKS TO DREW, JOE GUTTERI AND “SOME” U-TUBE FOLKS, MY ENTIRE SYSTEM IS NOW REBUILT. I WILL NOW MOVE ON TO ANOTHER OLD R-12 VEHICLE - MY 91 TOYOTA PREVIA (yes the one that looks like a big Egg – buy hey it’s a mid-engine Egg and it runs like it’s brand new except for AC).
